Air diffuser



June 10, 1958 TUTT 2,837,990-

' AIR [DIFFUSER Filed May 11. 1950 3mm RICHARD D. TUTT United States Patent AIR DIFFUSER Richard D. Tutt, New Britain, Conn., assignor, by mesne "assignments, to Allied Thermal Corporation, New

Britain, Conn., a corporation of Connecticut Application May 11, 1950, Serial No. 161,371 2 Claims. (Cl. 98-40) This invention relates to an air diffuser and more particularly, to an air diffuser of the type usually used in conjunction with a ceiling or overhead outlet such as is commonly used in air conditioning or distributing systerns for diffusing the air laterally or radially from the axis of the outlet into a room.

When conventional air diffusers are installed in ceiling outlets to diffuse air laterally of the outlet, i. e. generally parallel to the surface of the ceiling, there rapidly results every distinct and undesired darkening or smudging of the ceiling area surrounding the diffuser. In general, there will be observed, after a brief period of operation, a more or less concentrated ring of soot and other smudg-. ing particles adjacent the perimeter of the diffuser which is unsightly and generally necessitates frequent cleaning of the ceiling for sanitary appearance. This result has been" found to be true even in conjunction with air conditioning and distribution systems in which the air is filtered before being discharged from air diffusers of the type referred to, indicating that the principal source of soot and other smudging particles which form the unsightly ring around the diffuser is not the primary air being diffused but rather the air in the room into which the filtered primary air is introduced. Apparently it is I inherentinthe operation of conventional ceiling diffusers that some type of airflow results which causes dust particles from the room air to be concentrated and deposited It is an object of the present invention to provide an air diffusr embodying means operable to discharge air laterally or radially from the axis of the outlet in a manner so as to effectively avoid the ring-like unsightly smudging of the ceiling area surrounding the diffuser normally encountered with conventional diffusers and without at the same time adversely affecting the desired operating characteristics of the diffuser whereby effective and eflicient air diffusion may be obtained without the accompanying unsanitary and otherwise undesirable appearance of the wall or ceiling area heretofore considered unavoidable.

It is another object of the invention to provide an air diffuser of the type described which may be readily substituted for and used in place of conventional diffusers, which is simple and inexpensive to manufacture and install, and also pleasing and ornamental in appearance as well as being utilitarian.

Other objects will be in part obvious, and in part pointed out more in'detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

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In the drawing- Figure 1 is a cross sectional view of a fragmentary portion of an air duct outlet having connected thereto an air diffuser embodying the principles of the present invention.

Fig. 2 is a bottom plan view of the air diffuser illustrated in Fig. 1.

Referring to the drawing, in which like reference numerals are used to indicate like parts, Fig. 1 illustrates an exemplary installation of an air diffuser 10 embodying the principles of the present invention. The air diffuser 10 is shown in this figure adjacent the exit end of a duct collar 12 which may, for example, be part of a branch duct extending from a supply duct in a ceiling, said supply duct not being shown in the figure. The duct collar 12 terminates flush with the wall or ceiling surface 14.

In order to facilitate the installation of the air diffuser 10 and secure it adjacent the exit end of the duct collar 12, an angle ring 16 may be employed, if desired, and secured within the exit end of the duct collar 12, as illustrated in Fig. l. planar flange 18 which is disposed against the ceiling surface 14 and secured thereto in any suitable manner.

The air diffuser 10 comprises a plurality of annular vanes 20 which are concentric with and spaced from each other, terminating at their lower ends in laterally directedannular flanges 21 which deflect air moving axially through the collar 12' so as to project it transversely to the axis of the duct or collar in a direction substantially parallel with the wall surface 14 as indicated by the arrows illustrated in Fig. 1. The vanes 29 may be held in assembled relationship as indicated in Fig. l by any suitable means such as conventional assembly bars, not illustrated herein. The diffuser 10 also comprises a central cup-shaped vane member 22 which is surrounded by the which normally render the use of such diffusers so objcctionable.

As shown in the exemplary illustration, the outer vane 24 is annular and concentric with the vanes 20 and is so shaped that the inner portion of the outer vane 24 comprises an inward and upward directed flange 26 which is substantially parallel to the-corresponding flanges on the circular vanes 20. The flange 26 extends downwardly to form aconvexly curved ridge or projection 28 encircling the lower edges of the vanes and which is spaced outward from the ceiling or wall surface 14 when mounted in operative position, as shown in Fig. 1, and then merging with and extending laterally outward from the convexly curved ridge 28 there is a wide concavely arcuate skirt 30 which is of substantially greater width than the height of the ridge 28 so as to extend at a small angle to the wall surface 14, as clearly shown in Fig. 1. The skirt 30 forms a simple uninterrupted surface for air flow which is free from any abrupt turns, grooves, or the like. I

In the preferred embodiment of the invention, the

outer vane 24 is connected to the surrounded assembled circular vanes 20 by the assembly bars referred to above, whereby the outer vane 24, circular vanes 20, and central vane member 22 will comprise a unitary assembly which The angle ring 16 has an annular' may be secured in operative position within the duct outlet or collar 12 thereof by any suitable means such as a plurality of screws 32.

In operation, it is found that the outer .vane 24 cooperates with'the other vanes of the diffuser to cause the air deflected laterally by said'other vanes to be discharged in a direction parallel to the wall or ceiling surface 14 in such manner that the ring-like accumulation of soot and dust, or other discoloring particles on the wall surface surrounding the diffuser is very effectively avoided. Although it is not desired to limit the invention to a specific theory of operation, the following explanation may be helpful in understanding the invention. I have found by actual tests conducted with conventional diffusers that particles of dust originally present in the room air appear to migrate'to a position between the main air stream and the ceiling adjacent the periphery of the diffuser. While moving about in this vicinity, the dust particles first agglomerate into larger particles and in due course reach an apparently critical size such that they then disintegrate or explode spontaneously causing deposition onthe ceiling surfaces. Many attempts have been made to overcome this phenomenon heretofore such as by utilizing diffusers which are flush with the ceiling surfaces and thus theoretically provide an air flow which is not spaced from the ceiling surfaces, but all such attempts have been unsuccessful. By the use of a diffuser constructed in accordance with the present invention, it is believed that a similar migration and eventual agglomeration and disintegration of dust particles still takes place but with the important difference, however, that the agglomeration and disintegration occur over a wide area throughout the range of the diffuser thus decreasing the amount of smudge per unit area and effectively avoiding the unsightly ring-like concentration about the periphery of the diffuser which has been so undesirable heretofore. Accordingly, it is to be understood that it is not claimed that a diffuser constructed in accordance with the invention will entirely prevent discoloring of ceiling surfaces, but that any discoloring which may result is dispersed so widely and uniformly over the ceiling surface that it becomes practically unnoticeable and unobjectionable and there is not produced any ring-like concentration of dust particles of the type which normally accumulate adjacent conventional air diffusers.

From the foregoing, it will also be seen that the air diffuser embodying the principles of the present invention is capable of being simply and inexpensively manufactured and the installation thereof may be made at least as expeditiously and simply as the installation of conventional air diffusers of the circular vane type. the outer vane 24, while efficient and utilitarian to produce the above described results, is also very pleasing and ornamental in appearance.

While the invention has been illustrated and described in its preferred embodiment and has included certain details, it should be understood that'the invention is not to be limited to the precise details herein illustrated and described since the same maybe carried out in other ways, falling within the scope of the invention as claimed.

I claim as my invention:

1. In an air diffuser of the type for use with an air duct outlet in a wall surface and having a plurality of spaced R apart generally frusto-conical inner vanes for deflecting Further,

air laterally from the axis of said outlet, an anti-smudge ring extending about the periphery of the diffuser and forming throughout a continuous, smoothly curved, uninterrupted connecting surface between the diffuser and the wall surface, said ring comprising an annular sheet having an inner edge portion forming an outer vane of the diffuser and extending generally parallel to the inner vanes and a relatively wide peripheral skirt portion angularly related to the inner edge portion and engaging with the wall surface at its outer periphery, said inner edge portion and angularly related skirt portion forming a convex smoothly curved ridge projecting beyond the wall surface immediately adjacent the periphery of the air duct outlet and encircling the lower edges of the vanes, said skirt portion being of substantially greater width than the height of said ridge so as to extend toward the wall surface at a relatively small angle thereto.

2. In an air outlet device mounted with its front or air discharge end adjacent to a ceiling or Wall surface and which is operable to effect lateral discharge of air over said surface, an air guiding element of substantial width having a first portion forming a peripheral vane of the air outlet device and having a face portion extending laterally outward from said first portion and forming a continuation thereof, said face portion extending over a substantial portion of said ceiling or wall surface and being continuously and gradually curved first convexly outwardly and forwardly relative to the first portion of said element and then concavely outwardly and rearwardly with respect to said ceiling or Wall surface to guide air from the front end of said air outlet device toward said surface, said element terminating in an unbroken smooth peripheral edge portion resting against the ceiling or wall surface to guide the air substantially parallel to said air surface.

References Cited in the file of this patent UNITED STATES PATENTS Serre et a1. July 31, 1945 OTHER REFERENCES Aerofuse Outlet, Catalog No. 40, Tuttle and Bailey, received in Office November 6, 1940, page 4. 

